What You Need to Know on Smoking and Lung Cancer

If you quit smoking can you reduce or eliminate your risk of tobacco-related lung cancer, or is the damage permanent?

You can always reduce your risk if you quit smoking. If you're 50 years old and you've been a lifelong smoker and you quit smoking today, you reduce your risk by half. If you're 30 years old and a lifelong smoker, you can almost completely eliminate your risk of lung cancer by quitting.

There's some increased risk compared to the general population, if you have smoked. But, if you quit at the age of 30, it's almost a negligible increased risk.

If you've never been a smoker and you develop lung cancer, how did you get it? Is it genetics, environment, radon, luck of the draw?

There are two likely reasons. One, for whatever reason, you were born genetically predisposed to getting cancer. You have something in your cells that activated and started producing a tumor. That's probably one of the most likely reasons.

Then, there's the idea of environmental exposure, especially radon. Radon is the second leading risk factor for lung cancer in the United States, according to the American Cancer Society. Radon is a naturally occurring radioactive gas that comes from the Earth's soil. In fact, one in 15 homes have levels of radon that are considered too high. So home inspectors recommend that you get radon levels checked before buying new property, or to get radon sensors for the house.

But smoking is far and away the number one risk factor. About 80% of people who have lung cancer were smokers. You get a sense of the magnitude there.

Is there a difference between smoking-related lung cancer and non-smoking-related lung cancer?

It appears that the biggest difference is that people who are not smokers tend to do better overall. Their prognosis is better overall than people who have smoking-related lung cancer. But that probably has more to do with the fact that people who are not smoking are, overall, more fit. So they respond better to treatment. It may not have anything to do with the biology of the cancer; it just has to do with the physiology of the person.

Are certain types of lung cancer more treatable than others? What's the general survival rate?

If you catch a lung cancer early  a Stage 1 cancer  it's going to be more treatable than an advanced lung cancer. If you have a cancer that can be operated, that can be removed, you have a very good chance, a better chance than not, of being able to be cured. But the problem is that most people who go to doctor with some sort of symptom already have advanced lung cancer, so it's too late.

Survival rates for all lung cancer: in the first year, six out of 10 people will be dead. By the second year, eight out of 10 people will be dead. By five years, only 15% of people will survive.

When you talk about cancer in general, there are good screening programs, like mammograms for breast cancer or colonoscopies for colon cancer. With lung cancer, there is no generally accepted screening test today. We have 100 million former or current smokers in the United States right now and a lot of them, obviously, are considered at risk for lung cancer. But we haven't agreed on a way to screen all these people. We haven't come up with a reliable program. CT scans are too expensive. And should everyone be exposed to CT scans? That's still being figured out.

Are there differences between men and women in terms of susceptibility? Are there high-risk age groups?

A quickly growing population of people with lung cancer appears to be nonsmoking women. While men still have a greater number of overall lung cancer cases, nonsmoking women are much more likely than nonsmoking men to develop cancer. We don't know why that is, but we think it might have to do with changes in hormones. Women may be more likely to develop cancer because of hormonal changes. In terms of environmental exposure, if radon is in fact a culprit in the home and more women are at home than men, that could be part of the answer.

Most people are diagnosed at 50 or older. If you're diagnosed younger, it could mean that doctors caught the cancer earlier, which might mean that you have a very early stage cancer and were lucky to catch it. But it could also mean that if it's already advanced at such a young age, your prognosis may be even poorer than the prognosis for the general population.